Perfluoro carbon compounds



Patented Apr. 3, 1951 PERFLUORO CARBON COMPOUNDS Carl I. Gochenour, Niagara Falls, N. Y., assignor to Hooker Electrochemical Company, Niagara Falls, N. Y., a corporation of New York No Drawing. Application September 5, 1947, Serial No. 772,461

Difiuoro ethyne (CFECF) Tetrafiuoro propyne (CFECCFs) Hexafiuoro 2 butyne (CF3 E CCFs) HeXafiuoro-1butyne (FCECCFZCFs) Octafiuoro-Z-pentyne (CFcC ECCFzCFs) Octafluoro-l-pentyne (CFCCF2CF2CF3) Decafluoro-3-hexyne (CFsCFzCECCFzCFs) Decafluoro-2-hexyne CFsC 5 CCFzCFzCFx) Decafiuoro-l hexyne (CFE CCFzCFzCFzCFs) This list of compounds is given for purpose of illustration and is not intended to be limitative.

As an illustration of my process, I will describe it as exemplified by production of hexafluoro-Z- butyne.

In co-pending application Serial No. 593,775, filed May 14, 1945, now Patent No. 2,436,357, issued February 17, 1948, there is described a process for production of hexafluorodichlorobutene, by reaction of hexachlorobutadiene with hydrofluoric acid, or equivalent fiuorinating agent, as follows:

I have now discovered that the product of reaction 1 may be dechlorinated by reaction with a dehalogenation agent having a selective affinity for the halogen attached to the carbon atoms which are linked by a double bond, such as finely divided zinc, in a medium such as alcohol, e. g. ethyl alcohol, presumably asfollows:

CFsCCl: CClCFz +Zn CF30 E CCFs +ZnCl2 (2) Example Into a two gallon stainless steel reaction vessel, provided with an agitator, a packed exit column 2 feet long, a reflux condenser cooled with dry ice in methanol, and a receiver cooled with dry ice, were charged 3,000 ml. of 95 per cent ethyl alcohol and 1,126 grams of powdered zinc.

These materials were brought to 70 0., by means of an oil bath. With the agitator operating, 1,640 grams of 2,3 dichloro l,l,1,4,4,4, hexafluorobutene were introduced gradually, over a period of 12 14 Claims. (01. 260653) hours. During the first two hours all vapors were condensed and refluxed. When the temperature at the top of the column had reached C., the vapors were allowed to pass over into the receiver and there condensed. 'When all the reagent had been added, the temperature was raised to 90 0., and the agitation continued for a further period of one hour, until the reaction was complete, as indicated by rising vapor temperature.

The crude product collected was treated with phosphorous pentoxide to remove traces of alcohol, and then distilled, yielding 773 grams of a material having a boiling range between minus twenty-four and plus seven degrees Centigrade.

Analysis of the purified product showed it to contain 69.7 per cent fluorine, but no chlorine, and to have a molecular weight of 164 which corresponds closely to C4Fs.

Another compound having the analysis C4H6 and boiling at 113 C. has been described by Henne et al. (J. A. C. S., vol; 69, February 1947,

p. 280) This was reported to have the following structure:

r F i FzC-CF2 When oxidized by means of potassium permanganate the minor fraction produced by my process was found to yield potassium perfluoro succinate, which could only result from reaction with a cyclic compound, as follows:

This result leads me to believe that the minor fraction produced by my process is a mixture of the hexafiuorobutadiene of Miller et'al. and the hexafluorocyclobutene of Henne et al., but principally the latter. In any case, the major fraction of my product is obviously neither of these previously known compounds.

The major fraction of my product when oxidized by potassium permanganate yielded two mols of potassium trifluoroacetate, presumably as follows:

This reaction shows that the major fraction of my product has the symmetrical structure assumed, as indicated in reactions '2 and i4. a

The hexafluoro-2-butyne produced by reaction 2 is a stable, non-toxic colorless gas at ordinary temperature, and when condensed, a colorless liquid. It is useful as a refrigerant.

The analogous reactions for productionof the other compounds listed aboveare as renews;

cmccrcmcmcmcr z cagcgccrzcraorwancn (11y- All of these compounds are obviously of the type that lend themselves to polymerization.

They can also be oxidized to useful oxidation products, such as the potassium trifluoroacetate of reaction 4. 1 I 1 In reactions 2 and 5 to 12, it is to be understood that a suspension medium for the 'zinc is present. This should preferablyb'e'a solvent for zinc chloride; but for this purpose I do notwish to be limited to ethyl alcohol, 'as other solvents are available.

Neither do I wish to be limited to zinc as the other halogen atoms being fluorine, to.;substitute a triple bond for said double bond, which comprises reacting the olefin with a finely divided metal of the group consisting of iron, aluminum, magnesium and zinc, in a liquid medium inert with respect to the reaction.

2. The process for treatment'of perhalogenated aliphatic olefins of two to six carbon atoms having two adjacent carbon atoms linked by a double bond, and attached to each of said atoms,-a single halogen atom of the group consisting of chlorine and bromine, all other halogen atoms being fluorine, to substitute a triple bond for said double bond, which comprises reacting theolefin with a finely divided metal of the group consisting of iron, aluminum, magnesium and zinc, in a liquid medium inert with respect to the reaction.v

3. The process for treatment of perhalogenated aliphatic olefins of two to six carbon atoms having two adjacent carbon atoms linked by a double bond, and, attached to each of said atoms, aIsi-ngle chlorine atom, all other halogen atoms fbeing fluorine, to substitute mane bond for saiddoiible' 4 bond, which comprises agitating the olefin with finely divided metallic zinc, in a liquid medium inert with respect to the reaction.

4. The process for treatment of perhalogenated aliphatic olefins of two to six carbon atoms hav--- ing two adjacent carbon atoms linked by a double bond, and attached to e'a'ch oi 'saidatoms, a single chlorine atom, all other halogen atoms being fluorine, to substitute a triple bond for said double bond which comprises agitating the olefin with finely divided iron, in a liquid medium inert with respect to the reaction.

5. The process for treatment of perhalogenated aliphatic 'olefins of two to six carbon atoms having ,two adjacent carbon atoms linked by a double as, and, attached to each of said atoms, a single chlorine atom, all other halogen atoms bein'gPfl'uQrine, to substitute a triple bond for said double bond, which comprises agitating the olefin with finely divided magnesium, in a liquid medium inert with respect to the reaction. v e

6. The process for treatment of perhalogenated faliphatic olefins of two to six carbon atoms having twoadjacent carbon atoms linked by a double bond, and, attached to each of v said atoms, a

,single chlorine atom, all other halogen'atoms being fluorine, to substitute a triple bond for said double bond, which comprises, reacting the olefin with the finely divided metallic zinc in a medium inert with respect to the reaction.

'7. The process for treatment o'f pe'rhalogenated aliphatic olefins of two 'tosix carbonatomshaving two adjacent carbonatorhs 'link'edibya double bond, and, attached to each of said atoms, a single chlorine "atom, all other halogen atoms being fluorine, to substitute -atrijole bond for said double bond, w hic h comprises agitating the olefin with finely 'olivided metallidzinc in ethyl "alcohbl.

8. The process for treatment of 2,3 dichloi'o 1,1,l,4,l, 4 hexailuoro-2-butene, to substitute a triple "bond for the double bond, thereof, which comprises agitating it 'with'finely divided metallic z'inc,jinjethyl alcohol, at '70 to C., iii/:1 h recuring, and collecting the product in"a pressure vessel, at a temperature below 24 C. 4 A

. '9..As a new chemical "compound, hexafluoro butyn'e. I q g '10. As 'a new chemical compound, I hexaflu'oio- 2-.but'yn'e, boilingat 24 C. to ,23 C.

11. Aliphatic nuorcearbons having 'a bond.

12. Aliphatic fluorocarbons of twoto 'si'xcar'bon atoms having a triple bond.

-13. Compounds having the general formula CnF2n2 wherein n is a whole number greater than one. l4. Compounds having the g'ene ral formula cnFgn-z wherein n is 'a'whole number from two to six.

' time cant. I. socialism REFERENCES crrnp The following references are of record in the file of this "patent:

UNIT-eh smmsmmcrs a 'OTHER REFEREp "li i jet air llou'r. Am. Chem. "soc. volf c'v, 19h6-a"'(1945). 7 

1. THE PROCESS FOR TREATMENT OF PERHALOGENATED ALIPHATIC OLEFINS HAVING TWO ADJACENT CARBON ATOMS LINKED BY A DOUBLE BOND, AND, ATTACHED TO EACH OF SAID ATOMS, A SINGLE HALOGEN ATOM OF THE GROUP CONSISTING OF CHLORINE AND BROMINE, ALL OTHER HALOGEN ATOMS BEING FLUORINE, TO SUBSTITUTE A TRIPLE BOND FOR SAID DOUBLE BOND, WHICH COMPRISES REACTING THE OLEFIN WITH A FINELY DIVIDED METAL OF THE GROUP CONSISTING OF IRON, ALUMINUM, MAGNESIUM AND ZINC, IN A LIQUID MEDIUM INERT WITH RESPECT TO THE REACTION.
 11. ALIPHATIC FLUOROCARBONS HAVING A TRIPLE BOND. 